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Solvothermally‐Prepared Cu 2 O Electrocatalysts for CO 2 Reduction with Tunable Selectivity by the Introduction of p‐Block Elements
Author(s) -
Larrazábal Gastón O.,
Martín Antonio J.,
Krumeich Frank,
Hauert Roland,
PérezRamírez Javier
Publication year - 2017
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201601578
Subject(s) - selectivity , electrocatalyst , catalysis , reversible hydrogen electrode , high resolution transmission electron microscopy , x ray photoelectron spectroscopy , materials science , chemistry , ethylene , inorganic chemistry , chemical engineering , electrode , nanotechnology , electrochemistry , transmission electron microscopy , working electrode , organic chemistry , engineering
The electroreduction of CO 2 to fuels and chemicals is an attractive strategy for the valorization of CO 2 emissions. In this study, a Cu 2 O electrocatalyst prepared by a simple and potentially scalable solvothermal route effectively targeted CO evolution at low‐to‐moderate overpotentials [with a current efficiency for CO (CE CO ) of ca. 60 % after 12 h at −0.6 V vs. reversible hydrogen electrode, RHE], and its selectivity was tuned by the introduction of p‐block elements (In, Sn, Ga, Al) into the catalyst. SEM, HRTEM, and voltammetric analyses revealed that the Cu 2 O catalyst undergoes extensive surface restructuring (favorable for CO evolution) under the reaction conditions. The modification of Cu 2 O with Sn and In further enhanced the current efficiency (CE) for CO (ca. 75 % after 12 h at −0.6 V). In contrast, the introduction of Al altered the selectivity profile of the catalyst significantly, decreasing the selectivity toward CO but promoting the reduction of CO 2 to ethylene (CE≈7 %), n ‐propanol, and ethanol (CE≈2 % each) at −0.8 V vs. RHE. This result is related to a decreased reducibility of Al‐doped Cu 2 O that might preserve Cu + species (favorable for C 2 H 4 production) under the reaction conditions, which is supported by XRD, X‐ray photoelectron spectroscopy, and H 2 temperature‐programmed reduction observations.